One thing worth a try would be to add a cheap UV to the display and see if it knocks back the Dino’s. Depending on the type it may be effective. However, it’s pretty evident the biome of the tank is jacked (likely from all the chemi clean). Without seeing it in person, I’d either add some live rock/sand from a reputable source or tear it down and start with live rock and sand. Probably not what you want to hear but you could spend the next 6 months fighting this thing and pulling your hair out when the path of least resistance may be a restart with live rock. I’m concerned about the amount of chemi clean used. The system can recover in time but it could take a long time. Sorry you’re going through it. Totally sucks